This application claims priority to and hereby incorporates by reference Australian Patent Application No. 36354/00, filed May 22, 2000.
The present invention relates to a uterine cannula and pelvic support for gynecological laparoscopy.
Gynecological laparoscopic surgery requires a pelvic assistant to hold and manipulate uterine cannulas at the command of the gynecologist.
Two types of known uterine cannulas are the Leech-Wilkinson intra-uterine cannula and the Spackman intra-uterine cannula. The Leech-Wilkinson cannula is in the form of an elongate hollow tube having a threaded cone provided about its distal end. The cannula is inserted through the vagina and the cone threading engaged with the cervix by rotation of the cannula to thereby seal the uterus. Fluid is then passed through the cannula to inflate the uterus and check for blockages. It is found that the cone seal formed at the end of the Leech-Wilkinson cannula forms a particularly effective seal preventing the leakage of fluid used during hydro tubation. However, a significant drawback with the Leech-Wilkinson cannula is that it does not allow intra-uterine manipulation during hydro tubation.
The Spackman cannula is in the form of a elongate hollow tube having a bulb formed at a distal end for forming a press seal with the cervix and a curved manipulator formed integrally with the bulb that extends into the uterus. The manipulator is provided with one or more outlet ports so that fluid can be delivered by the cannula into the uterus. The manipulator at the end of the Spackman cannula does allow for a small degree of intra-uterine manipulation. However in practice the seal formed by the bulb at the end of the cannula is often ineffective. As a result, substantial volume of the fluid may leak passed the cervix making the hydro tubation procedure inconclusive. To overcome this problem the Spackman cannula is provided with an adjustable plate for holding vulsellum forceps. The forceps are used to pinch the cervix into tight contact with the bulb to improve the seal. However it would be appreciated that when the vulsellum forceps are used, the manipulator can only be turned by a limited degree because the forceps would otherwise cause tearing of the cervix. Therefore in order to effectively use the manipulator on the Spackman cannula, the forceps must be released during manipulation thereby leading to a deterioration in the seal formed with the cervix. Further, the intra uterine tip of the Spackman cannula has a fixed length.
The use of the pelvic assistant during gynecological laparoscopy have several drawbacks. For long procedures, for example sometimes up to 20 minutes in a set position, the assistant becomes physically fatigued and is unable to maintain the desired orientation of the cannula. A further disadvantage is that because the assistant relies on oral instructions from the doctor the correct positioning of the cannula is an iterative process and therefore the time taken to correctly position the cannula is significantly greater than would be the case if the doctor could adjust the position. Further, the use of an assistant increases costs of the procedure as the assistant becomes a dedicated member of the surgical team.
More recently there has been a trend towards total laparoscopic hysterectomy and laparoscopic pelvic floor repair. Various devices have been incorporated to help facilitate this procedure, from uterine manipulators to vaginal tubes. The use of the vaginal tubes has been to provide cervical-vaginal delineation. Some of the uterine manipulators, although efficient, are difficult to use, have various parts that are easily misplaced and are, in general, bulky instruments. Moreover, almost all of them require a pelvic assistant, usually a doctor or a nurse, to hold the manipulator in place during the operation or to move it on command by the laparoscopic surgeon.
In the current art form, during total laparoscopic vaginal delivery, the vaginal vault is divided from the cervix to enable delivery of the uterus through the vagina. Various vaginal tubes have been used to delineate tissue plane and facilitate this procedure. The vaginal tubes may be made from various materials. A metal tube is used by surgeons who use CO2 lasers to cut the vaginal vault, while a plastic tube is used by those who use electrocautery, as it does not conduct electricity.
In the current art form, the surgeon requires a pelvic assistant, usually a nurse or a doctor, during laparoscopic surgery. Fatigue and musculo-skeletal problems are some of the costs to the pelvic assistant. For the hospital, it is costly to assign staff to carry out mechanical and time consuming tasks. The assistant will be required from time to time, at the direction of the surgeon, to change the position of the manipulator or vaginal tube. Firm pressure is required to keep the vaginal vault taut and while it is being divided from the cervix. Failure to maintain pressure on the vaginal vault, via the tube, may result in excessive bleeding. The vaginal wall is stretched, resulting in the blood vessels in the vaginal tissue being compressed by the pressure of the tube against the vaginal vault, thus resulting in the blood vessels being sealed during incision of the vaginal vault. The bladder may also be in danger of being damaged if pressure is lost during excision, as the edge of the vaginal tube keeps the bladder away from the vaginal wall as it is being incised. Uncontrolled or sudden loss of pressure and the tube against the vagina may result in excessive bleeding or bladder damage.
After the cervix has been detached from the vaginal vault, the uterus is delivered through the vaginal vault. Loss of pneumoperitoneum occurs and insertion of a vaginal tube with a sealed end is required to restore the pneumoperitoneum. A suture is usually placed in the hollow of the tube before it is inserted into the vagina. The needle of the suture is picked up with a laparoscopic needle holder and the vaginal vault sutured laparoscopically. The needle is then pushed through the vault into the vaginal tube for extraction as the vaginal tube is withdrawn from the vagina. A knot is made in the suture and secured through the vagina.
From time to time during the procedure an assistant is required to rotate the vaginal tube and hold it in position as requested by the surgeon.
Laparoscopic pelvic floor repair requires a vaginal probe and a rectal probe to delineate both structures to the laparoscopic surgeon. A pelvic assistant is therefore required to hold both probes. The availability of a pelvic assistant has been previously mentioned above.
It is an object of the present invention to provide a medical instrument that facilitates a high degree of control and manipulation of the uterus during gynecological surgery.
According to the present invention there is provided a medical instrument for gynecological surgery comprising at least:
a cervical funnel having an elongated hollow tube with a proximal end for insertion into the vagina of a patient and a hollow substantially cone-shaped member provided at the proximal end of the hollow tube, the cone-shaped member having an outer diameter that reduces in a direction extending toward a distal end of the hollow tube and having a mouth with an inner diameter greater than the diameter of the opening of the patient""s cervix; and,
an intra-uterine cannula having: an outer sheath axially and rotatably moveable within said hollow tube, the outer sheath having a proximal end and an opposite distal end respectively locatable outside the proximal and distal ends of the hollow tube; sealing means provided at the proximal end of the sheath for engaging the cervix to seal the patient""s uterus; and, an inner manipulation shaft axially and rotatably moveable within the outer sheath and extending axially through the sealing means.
Preferably the mouth of said cone-shaped member is formed with a protruding lip that extends along a portion of the circumference of the mouth for lifting a section of the vaginal vault away from adjacent internal organs.
Preferably the lip extends about the circumference of the mouth through an arc that subtends an angle of about 120xc2x0.
Preferably the lip protrudes at an angle of about 45xc2x0 to the longitudinal axis of the cone-shaped member, for a distance of about 5 mm to 10 mm.
Advantageously, a mark is provided at the distal end of the hollow tube corresponding to the angular position of a midpoint of said lip so that a surgeon can visualize the position of the lip during a surgical procedure.
Preferably said cone-shaped member is made from a plastics material.
Preferably the cone-shaped member has a maximum outside diameter of between 30 mm to 50 mm, and more typically between 40 mm to 45 mm.
Preferably said cone-shaped member is removably attached to the proximal end of the hollow tube to facilitate replacement if damaged during a surgical procedure.
Preferably said hollow tube is made from an autoclavable material including stainless steel and has an outside diameter of between 10 mm to 30 mm, and more typically between 15 mm to 20 mm.
Preferably said sealing means is in the form of a cone having a thread formed along its outer surface with a large diameter end of the cone disposed adjacent the proximal end of said outer sheath.
Preferably said medical instrument further includes releasable locking means for releasably locking said inner manipulation shaft to said outer sheath.
Preferably said medical instrument further includes a support for supporting said intra-uterine cannula and cervical funnel, said support including an arm for coupling to a patient support to allow adjustment of the position of the support in a direction of the length of the arm; an adjustable joint attached to the arm providing at least one further degree of motion; an extendible member coupled to the joint; and, an instrument holder attached to an end of the extendible member for holding said intra-uterine cannula.
Preferably said joint provides three degrees of rotational motion to allow pitch, roll and yaw position control of the extendible member and thus the cannula.
Preferably the joint is a ball joint provided with releasable locking means which, when in the locked state, locks the position of the extendible member and when in the unlocked state allows adjustment of the position of the extendible member.
Preferably the extendible member is telescopically extendible.
Preferably said support further includes a clamp for releasably coupling the extendible member to the joint to allow adjustment of the position of the extendible member in a direction of its length.